You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
225 lines
10 KiB
225 lines
10 KiB
3 years ago
|
"""This will be the home for the policy that hooks in the new
|
||
|
|
code that adds all the email6 features.
|
||
|
|
"""
|
||
|
|
|
||
|
|
import re
|
||
|
|
import sys
|
||
|
|
from email._policybase import Policy, Compat32, compat32, _extend_docstrings
|
||
|
|
from email.utils import _has_surrogates
|
||
|
|
from email.headerregistry import HeaderRegistry as HeaderRegistry
|
||
|
|
from email.contentmanager import raw_data_manager
|
||
|
|
from email.message import EmailMessage
|
||
|
|
|
||
|
|
__all__ = [
|
||
|
|
'Compat32',
|
||
|
|
'compat32',
|
||
|
|
'Policy',
|
||
|
|
'EmailPolicy',
|
||
|
|
'default',
|
||
|
|
'strict',
|
||
|
|
'SMTP',
|
||
|
|
'HTTP',
|
||
|
|
]
|
||
|
|
|
||
|
|
linesep_splitter = re.compile(r'\n|\r')
|
||
|
|
|
||
|
|
@_extend_docstrings
|
||
|
|
class EmailPolicy(Policy):
|
||
|
|
|
||
|
|
"""+
|
||
|
|
PROVISIONAL
|
||
|
|
|
||
|
|
The API extensions enabled by this policy are currently provisional.
|
||
|
|
Refer to the documentation for details.
|
||
|
|
|
||
|
|
This policy adds new header parsing and folding algorithms. Instead of
|
||
|
|
simple strings, headers are custom objects with custom attributes
|
||
|
|
depending on the type of the field. The folding algorithm fully
|
||
|
|
implements RFCs 2047 and 5322.
|
||
|
|
|
||
|
|
In addition to the settable attributes listed above that apply to
|
||
|
|
all Policies, this policy adds the following additional attributes:
|
||
|
|
|
||
|
|
utf8 -- if False (the default) message headers will be
|
||
|
|
serialized as ASCII, using encoded words to encode
|
||
|
|
any non-ASCII characters in the source strings. If
|
||
|
|
True, the message headers will be serialized using
|
||
|
|
utf8 and will not contain encoded words (see RFC
|
||
|
|
6532 for more on this serialization format).
|
||
|
|
|
||
|
|
refold_source -- if the value for a header in the Message object
|
||
|
|
came from the parsing of some source, this attribute
|
||
|
|
indicates whether or not a generator should refold
|
||
|
|
that value when transforming the message back into
|
||
|
|
stream form. The possible values are:
|
||
|
|
|
||
|
|
none -- all source values use original folding
|
||
|
|
long -- source values that have any line that is
|
||
|
|
longer than max_line_length will be
|
||
|
|
refolded
|
||
|
|
all -- all values are refolded.
|
||
|
|
|
||
|
|
The default is 'long'.
|
||
|
|
|
||
|
|
header_factory -- a callable that takes two arguments, 'name' and
|
||
|
|
'value', where 'name' is a header field name and
|
||
|
|
'value' is an unfolded header field value, and
|
||
|
|
returns a string-like object that represents that
|
||
|
|
header. A default header_factory is provided that
|
||
|
|
understands some of the RFC5322 header field types.
|
||
|
|
(Currently address fields and date fields have
|
||
|
|
special treatment, while all other fields are
|
||
|
|
treated as unstructured. This list will be
|
||
|
|
completed before the extension is marked stable.)
|
||
|
|
|
||
|
|
content_manager -- an object with at least two methods: get_content
|
||
|
|
and set_content. When the get_content or
|
||
|
|
set_content method of a Message object is called,
|
||
|
|
it calls the corresponding method of this object,
|
||
|
|
passing it the message object as its first argument,
|
||
|
|
and any arguments or keywords that were passed to
|
||
|
|
it as additional arguments. The default
|
||
|
|
content_manager is
|
||
|
|
:data:`~email.contentmanager.raw_data_manager`.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
message_factory = EmailMessage
|
||
|
|
utf8 = False
|
||
|
|
refold_source = 'long'
|
||
|
|
header_factory = HeaderRegistry()
|
||
|
|
content_manager = raw_data_manager
|
||
|
|
|
||
|
|
def __init__(self, **kw):
|
||
|
|
# Ensure that each new instance gets a unique header factory
|
||
|
|
# (as opposed to clones, which share the factory).
|
||
|
|
if 'header_factory' not in kw:
|
||
|
|
object.__setattr__(self, 'header_factory', HeaderRegistry())
|
||
|
|
super().__init__(**kw)
|
||
|
|
|
||
|
|
def header_max_count(self, name):
|
||
|
|
"""+
|
||
|
|
The implementation for this class returns the max_count attribute from
|
||
|
|
the specialized header class that would be used to construct a header
|
||
|
|
of type 'name'.
|
||
|
|
"""
|
||
|
|
return self.header_factory[name].max_count
|
||
|
|
|
||
|
|
# The logic of the next three methods is chosen such that it is possible to
|
||
|
|
# switch a Message object between a Compat32 policy and a policy derived
|
||
|
|
# from this class and have the results stay consistent. This allows a
|
||
|
|
# Message object constructed with this policy to be passed to a library
|
||
|
|
# that only handles Compat32 objects, or to receive such an object and
|
||
|
|
# convert it to use the newer style by just changing its policy. It is
|
||
|
|
# also chosen because it postpones the relatively expensive full rfc5322
|
||
|
|
# parse until as late as possible when parsing from source, since in many
|
||
|
|
# applications only a few headers will actually be inspected.
|
||
|
|
|
||
|
|
def header_source_parse(self, sourcelines):
|
||
|
|
"""+
|
||
|
|
The name is parsed as everything up to the ':' and returned unmodified.
|
||
|
|
The value is determined by stripping leading whitespace off the
|
||
|
|
remainder of the first line, joining all subsequent lines together, and
|
||
|
|
stripping any trailing carriage return or linefeed characters. (This
|
||
|
|
is the same as Compat32).
|
||
|
|
|
||
|
|
"""
|
||
|
|
name, value = sourcelines[0].split(':', 1)
|
||
|
|
value = value.lstrip(' \t') + ''.join(sourcelines[1:])
|
||
|
|
return (name, value.rstrip('\r\n'))
|
||
|
|
|
||
|
|
def header_store_parse(self, name, value):
|
||
|
|
"""+
|
||
|
|
The name is returned unchanged. If the input value has a 'name'
|
||
|
|
attribute and it matches the name ignoring case, the value is returned
|
||
|
|
unchanged. Otherwise the name and value are passed to header_factory
|
||
|
|
method, and the resulting custom header object is returned as the
|
||
|
|
value. In this case a ValueError is raised if the input value contains
|
||
|
|
CR or LF characters.
|
||
|
|
|
||
|
|
"""
|
||
|
|
if hasattr(value, 'name') and value.name.lower() == name.lower():
|
||
|
|
return (name, value)
|
||
|
|
if isinstance(value, str) and len(value.splitlines())>1:
|
||
|
|
# XXX this error message isn't quite right when we use splitlines
|
||
|
|
# (see issue 22233), but I'm not sure what should happen here.
|
||
|
|
raise ValueError("Header values may not contain linefeed "
|
||
|
|
"or carriage return characters")
|
||
|
|
return (name, self.header_factory(name, value))
|
||
|
|
|
||
|
|
def header_fetch_parse(self, name, value):
|
||
|
|
"""+
|
||
|
|
If the value has a 'name' attribute, it is returned to unmodified.
|
||
|
|
Otherwise the name and the value with any linesep characters removed
|
||
|
|
are passed to the header_factory method, and the resulting custom
|
||
|
|
header object is returned. Any surrogateescaped bytes get turned
|
||
|
|
into the unicode unknown-character glyph.
|
||
|
|
|
||
|
|
"""
|
||
|
|
if hasattr(value, 'name'):
|
||
|
|
return value
|
||
|
|
# We can't use splitlines here because it splits on more than \r and \n.
|
||
|
|
value = ''.join(linesep_splitter.split(value))
|
||
|
|
return self.header_factory(name, value)
|
||
|
|
|
||
|
|
def fold(self, name, value):
|
||
|
|
"""+
|
||
|
|
Header folding is controlled by the refold_source policy setting. A
|
||
|
|
value is considered to be a 'source value' if and only if it does not
|
||
|
|
have a 'name' attribute (having a 'name' attribute means it is a header
|
||
|
|
object of some sort). If a source value needs to be refolded according
|
||
|
|
to the policy, it is converted into a custom header object by passing
|
||
|
|
the name and the value with any linesep characters removed to the
|
||
|
|
header_factory method. Folding of a custom header object is done by
|
||
|
|
calling its fold method with the current policy.
|
||
|
|
|
||
|
|
Source values are split into lines using splitlines. If the value is
|
||
|
|
not to be refolded, the lines are rejoined using the linesep from the
|
||
|
|
policy and returned. The exception is lines containing non-ascii
|
||
|
|
binary data. In that case the value is refolded regardless of the
|
||
|
|
refold_source setting, which causes the binary data to be CTE encoded
|
||
|
|
using the unknown-8bit charset.
|
||
|
|
|
||
|
|
"""
|
||
|
|
return self._fold(name, value, refold_binary=True)
|
||
|
|
|
||
|
|
def fold_binary(self, name, value):
|
||
|
|
"""+
|
||
|
|
The same as fold if cte_type is 7bit, except that the returned value is
|
||
|
|
bytes.
|
||
|
|
|
||
|
|
If cte_type is 8bit, non-ASCII binary data is converted back into
|
||
|
|
bytes. Headers with binary data are not refolded, regardless of the
|
||
|
|
refold_header setting, since there is no way to know whether the binary
|
||
|
|
data consists of single byte characters or multibyte characters.
|
||
|
|
|
||
|
|
If utf8 is true, headers are encoded to utf8, otherwise to ascii with
|
||
|
|
non-ASCII unicode rendered as encoded words.
|
||
|
|
|
||
|
|
"""
|
||
|
|
folded = self._fold(name, value, refold_binary=self.cte_type=='7bit')
|
||
|
|
charset = 'utf8' if self.utf8 else 'ascii'
|
||
|
|
return folded.encode(charset, 'surrogateescape')
|
||
|
|
|
||
|
|
def _fold(self, name, value, refold_binary=False):
|
||
|
|
if hasattr(value, 'name'):
|
||
|
|
return value.fold(policy=self)
|
||
|
|
maxlen = self.max_line_length if self.max_line_length else sys.maxsize
|
||
|
|
lines = value.splitlines()
|
||
|
|
refold = (self.refold_source == 'all' or
|
||
|
|
self.refold_source == 'long' and
|
||
|
|
(lines and len(lines[0])+len(name)+2 > maxlen or
|
||
|
|
any(len(x) > maxlen for x in lines[1:])))
|
||
|
|
if refold or refold_binary and _has_surrogates(value):
|
||
|
|
return self.header_factory(name, ''.join(lines)).fold(policy=self)
|
||
|
|
return name + ': ' + self.linesep.join(lines) + self.linesep
|
||
|
|
|
||
|
|
|
||
|
|
default = EmailPolicy()
|
||
|
|
# Make the default policy use the class default header_factory
|
||
|
|
del default.header_factory
|
||
|
|
strict = default.clone(raise_on_defect=True)
|
||
|
|
SMTP = default.clone(linesep='\r\n')
|
||
|
|
HTTP = default.clone(linesep='\r\n', max_line_length=None)
|
||
|
|
SMTPUTF8 = SMTP.clone(utf8=True)
|